textproduct: Albany

WHAT HAS CHANGED

No significant changes with this forecast update.

KEY MESSAGES

1) Scattered showers and thunderstorms return for the end of the work week, bringing the potential for locally heavy rain and isolated damaging wind gusts, particularly on Thursday.

2) Increasing heat and humidity also return Thursday into Friday, which may result in heat-related impacts, mainly in the Mid-Hudson Valley.

DISCUSSION

KEY MESSAGE 1...

High pressure ridging will shift eastward throughout the day today, giving way to meager height falls aloft as a weak trough and shortwave advance towards the eastern Great Lakes. While these features won't quite rotate into our region, they will be the driving forcing mechanisms behind scattered showers and thunderstorms beginning Thursday and again on Friday. Overall, the forcing associated with this system is very weak. However, our position relative to a strengthening Bermuda High will ensure warm, moist air gets ushered into the region and force requisite destabilization to support convective development.

The challenge with Thursday's forecast, particularly pertaining to the potential for isolated severe storms, lies with the extent of cloud cover. A weak surface disturbance will pass by to our south tonight, driving some initial showers and clouds early tomorrow morning. With moisture advection marrying up to the height falls with the incoming trough, it is very possible that we could have sufficient coverage to limit severe- level storm growth. That said, given the high level of heat and humidity (see KEY MESSAGE 2 for additional details), latest CAMs indicate moderate instability with weak to modest deep layer shear particularly within the Capital District and areas south where SPC has introduced a Marginal Risk (Level 1 of 5) for severe weather. Isolated strong to severe storms are therefore possible with strong to locally damaging winds the primary hazard due to precipitation loading and dynamic cooling (lapse rates ~6 C/km). Any shower or storm will also therefore be capable of producing moderate to heavy downpours given unseasonably high PWATs (~2 STDEVs above normal) up to 2" and tall, skinny CAPE profiles. We will have to monitor especially our urban areas for potential isolated flash flooding given very wet antecedent conditions after last week's event.

KEY MESSAGE 2...

The aforementioned Bermuda High building to our southeast will be responsible for driving heat and humidity back to uncomfortable levels on Thursday and Friday. Geopotential heights reaching ~2 STDEVs above normal along with anomalous moisture content courtesy of persistent southwesterly flow will drive highs widely into the mid to upper 80s with dewpoints in the upper 60s to low 70s both days. Cloud cover remains a question on Thursday so the magnitude of heat and humidity therefore is also somewhat uncertain. However, confidence is high that the greatest feels-like temperatures will be located in Valley areas both days where heat index values will reach the low to potentially mid/upper 90s. Heat Advisories may be needed in the near future particularly for portions of the Mid-Hudson Valley.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Patchy ground fog may produce intermittent IFR/LIFR Vsbys/Cigs through daybreak at KGFL and KPSF. Otherwise, VFR conditions are expected through at least 03Z/Thu, with mainly high/mid level clouds expected. Some rain showers may develop at KPOU between 04Z-06Z/Thu, possibly producing MVFR Cigs and Vsbys. Light/variable winds overnight will become south to southwest at 4-8 KT by late morning, then will become light/variable again after sunset.

Outlook...

Thursday Night: Low Operational Impact. Isolated SHRA...TSRA. Friday: High Operational Impact. Numerous SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: High Operational Impact. Likely SHRA...TSRA. Saturday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Sunday: Low Operational Impact. Slight Chance of SHRA...TSRA. Sunday Night: Low Operational Impact. Slight Chance of SHRA. Monday: Moderate Operational Impact. Chance of SHRA...TSRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.